ETH Zurich Concrete Boat

ETH Zurich, a team of researchers operating in the largest Swiss city, have for the third year in a row won a Design Innovation award. This year, it was for their 3D printed concrete canoe.

The Concrete Canoe Regatta, a two-day long race, takes place in Cologne, Germany, every other year. Over 1,000 participants from universities all over Europe raced 90 boats made entirely from concrete on the Rhine river. Competing for the lightest, fastest, most beautiful boat, 89 of the boats were no match for ETH Zurich’s entry, which utilised the latest 3D printing technology and brought home the most coveted award of the lot: Design Innovation.

ETH has been participating in the Regatta since 2005, and finds itself now as the team to beat, having dominated the competition for a three-year spell. The Concrete Canoe Regatta has served ETH as a prototyping framework for emerging research projects. Previously technologies such as, Mesh Mold and Smart Dynamic Casting, have been tested at the Regatta, and since become successful mature researches. This year, DBT's Free Formwork was the research which drove the development of the canoe, and it was highly praised by the jury for its unique design.

ETH Zurich DBT-Concrete-Canoe-regatta

The 3D printed plastic formwork of the concrete canoe.

A collaboration which enlisted the help of DBT, who provided the computational design and digital fabrication expertise, as well as the PCBM Group, who developed the concrete mixes and processes used in the construction of the model, ETH Zurich’s 114 Kilogram SkelETHon brought the Design Innovation prize back to Zurich for a third year in succession.

The four-metre long boat boasts a stiff steel fibre-reinforced concrete inner skeleton, ensuring the boat remains durable. This is covered by three-millimetre-thick waterproof skin, also made with concrete. Such a wealth of concrete would normally mean a heavy model, which would need a lot of force to drive. But with topology and shape optimisation algorithms, the use of material was reduced significantly. The material that was used was distributed in a skeleton-like structure, giving the boat its name, while maximising the stiffness of the boat, without hindering its aero-dynamics.

Fabricating the skeleton, a sub-millimetre-thin plastic formwork was 3D printed in transparent PLA, using Fused Deposition Modelling technology. It was then cast in ultra-high performance, fibre-reinforced concrete. The 3D printed formwork, the only use of 3D printing in the whole project, has been cited by the researchers as the main factor in producing a lightweighted model, weighing at just over four kilograms.

“The construction process made possible a highly complex concrete skeleton with bones as thin as 15 millimetres in diameter which would be impossible to fabricate with any other digital fabrication technologies. 3D printing, a precious fabrication process, was used minimally, but had significant impact on the overall design,” a blog by DTB on the canoe reads.

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